Fast FLAIR sequence structure. Typical FSE sequence structure of multiple 180° pulses is modified by addition of a 180° inversion pulse, followed by a delay time until the alpha pulse (inversion time or TI). CSF is suppressed by appropriate selection of inversion time, which for FLAIR is approximately 2000 ms. Effective TE is determined by low-amplitude phase-encoding steps (central k-space). S = slice-select direction, R = “read” or frequency-encode direction, P = phase-encode direction
No comments:
Post a Comment